JP4750838B2 - Universal joint - Google Patents

Description

  The present invention relates to a universal joint, and more particularly to a slip bush of a universal joint, and a power transmission unit arranged along a circumference and having a pin inserted in the middle thereof, and the power transmission unit By forming a C-shaped cross-section elastic part that is assembled in a crimped state when the slip bushing is assembled, the strength and rigidity can be improved even if the universal joint is twisted. The present invention relates to a universal joint capable of minimizing an increase in clearance due to wear, pressing, and the like and generation of noise.

  Generally, when a driver rotates a steering wheel in a desired direction, a steering shaft connected to the steering wheel rotates, and the steering shaft is racked via a universal joint. Rotational force is transmitted to a gear box composed of a pinion gear. At this time, the gear box changes the rotational motion of the steering shaft into a linear motion by the rack and pinion gear and transmits it to the rack bar, and the rack bar transmits the force to the tie rod connected to the tire knuckle to move the vehicle in the traveling direction. Can be changed.

  In particular, the shaft between the steering shaft and the gearbox has a structure in which the input shaft and the output shaft do not coincide with each other on the coaxial line, and is inclined at a certain angle. Since it is not possible, it is essential to use a universal joint whose steering axis can be changed to a certain angle.

  FIG. 1 is an exploded perspective view showing a universal joint according to the prior art, and FIG. 2 is a perspective view showing a slip bush according to the prior art.

  As illustrated, the universal joint 100 connected to the steering shaft and transmitting the rotational movement of the steering wheel to the gear box includes a tube 110 and a shaft 120, and the shaft 120 mediates a slip bush 130. Thus, the structure is inserted into the tube 110.

  The tube 110 has an inner diameter processed into an appropriate shape so that the C-shaped elastic section 140 and the solid section 150 formed along the circumference of the slip bush 130 are smoothly guided, and the outer periphery of the slip bush 130 is formed. Abut and join.

  Further, the shaft 120 has an outer diameter processed in conformity with the shape of the elastic portion 140 and the solid portion 150 of the slip bush 130 so that one side can be inserted into the slip bush 130 and is in contact with the inner peripheral surface of the slip bush 130 to be coupled.

  As described above, the coupling structure of the tube 110 and the shaft 120 of the universal joint 100 to which the slip bush 130 is attached absorbs the impact transmitted from the wheel and extends in the axial direction in order to improve the assembling property. Although it is provided so that it can contract, it absorbs the kick-back load generated by the impact applied to the wheels due to the unevenness of the road surface during traveling, and it slides in the axial direction when assembling to the steering column and gear box So that it is easy to assemble.

  In general, the slip bush 130 is formed of a plastic material, and is formed in a cylindrical shape so that the three elastic portions 140 and the three solid portions 150 are alternately arranged along the circumference of the slip bush 130 while maintaining a constant interval. Is formed.

  The solid portion 150 is formed in a cylindrical shape, and half of the cylinder is formed along the outer peripheral surface of the slip bush 130, and the remaining half is formed so as to be symmetric along the inner peripheral surface of the slip bush 130. The elastic portion 140 is also formed so as to be symmetric along the outer peripheral surface and the inner peripheral surface of the slip bush 130, and the elastic portion 140 is a hollow cylindrical form with a constant portion formed on the outer peripheral surface side of the slip bush 130. The surface is cut in the longitudinal direction, and the cross-sectional shape is formed in the form of “C”.

  In the slip bush 130 according to the related art configured as described above, when the shaft 120 slides into the tube 110 with the torsional torque and the rotational torque being applied, the solid portion 150 contacts the inner peripheral surface of the tube 110. Thus, the sliding frictional force is increased by the frictional force between the solid part 150 and the tube 110, and the torsional fracture strength of the slip bush 130 is ensured.

  However, when the solid portion 150 of the slip bush 130 according to the prior art is formed integrally with the slip bush 130 and is slid in a state where rotational torque is applied to the shaft 120, the entire outer peripheral surface of the solid portion 150 is the same. Since the state in contact with the tube 110 is maintained, there is a problem in that the sliding frictional force increases and the safety factor against torsional fracture strength decreases.

  Here, the problem of a decrease in the safety factor with respect to the torsional fracture strength is that, in the case of the conventional slip bush 130, most of the load in the process of transmitting the rotational force between the shaft 120 and the tube 110 is the solid portion 150 of the slip bush 130. However, depending on the material characteristics of the slip bush 130, which is the same material as the solid portion 150, when a strong rotational force is applied in a short time, the solid portion 150 of the slip bush 130 may be destroyed. Yes, when such a phenomenon occurs, steering is impossible, which means that a big problem occurs in the safety of the automobile.

  If the conventional slip bush 130 is used and a torsional impact is applied to the universal joint 100, the sliding frictional force between the solid portion 150 of the slip bush 130 and the inner peripheral surface of the tube 110 increases. As the solid portion 150 wears, there is a problem that a clearance increases between the solid portion 150 and the tube 110 and noise is generated.

  The present invention is arranged along a circumference and formed with a power transmission part in which a pin is inserted in the middle, and spaced apart from the power transmission part at a predetermined interval. By forming an elastic part with a C-shaped cross section to be assembled in a crimped state on the slip bush, even if the universal joint is twisted, the strength and rigidity are improved, increasing the clearance due to wear and pressing, etc. and generating noise It is an object of the present invention to provide a universal joint that can minimize the above.

To achieve this object, the present invention is a universal joint comprising a hollow tube, a slip bush inserted into the tube, and a shaft coupled to the tube via the slip bush. The slip bush is arranged in the axial direction along the circumference of the slip bush and includes a power transmission portion provided with a pin in the middle and a support portion for supporting both ends of the pin, and a circumference of the slip bush. are arranged along, and are spaced apart with the power transmission part, one side viewed contains an elastic portion of the C-shaped cross-section which is notched in the axial direction, a tapered portion is formed on both side ends of the pin characterized in that that.

  According to the present invention, a power transmission portion arranged along the circumference and having a pin inserted in the middle thereof, and formed at a predetermined interval from the power transmission portion, when assembling the slip bush, By forming an elastic part with a C-shaped cross section to be assembled in a crimped state on the slip bush, even if the universal joint is twisted, the strength and rigidity are improved, increasing the clearance due to wear and pressing, etc. and generating noise The effect of minimizing is obtained.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to components in each drawing, it should be noted that the same components are given the same reference numerals as much as possible even if they are displayed on other drawings. Don't be. In the description of the present invention, when it is determined that a specific description of a related known configuration or function will obscure the gist of the present invention, a detailed description thereof will be omitted.

  FIG. 3 is an exploded perspective view showing the universal joint according to the first embodiment of the present invention.

  The universal joint 200 according to the first embodiment of the present invention includes a shaft 210 that is inserted into the inner periphery of the slip bush 240 and a hollow tube 220 that houses the slip bush 240 into which the shaft 210 is inserted. Composed.

  One end of the shaft 210 is connected to a steering shaft (not shown), and a first coupling groove 230 is machined along the outer peripheral surface at the other end. Here, at least two first coupling grooves 230 are formed along the outer peripheral surface of the other end of the shaft 210 so as to come into contact with the elastic portion 250 and the power transmission portion formed along the circumference of the slip bush 240. However, the present invention is not limited to this, and may be variously formed according to the number of elastic portions 250 and power transmission portions formed on the slip bush 240.

  The inner diameter of the tube 220 is processed to match the outer peripheral surface shape of the slip bush 240 so that the shaft 210 having the first coupling groove 230 formed at one end and the slip bush 240 attached to the shaft 210 can be inserted. Is done. That is, the elastic portion 250 and the support portion 260 of the slip bush 240 and the pin 270 inserted and supported in the middle of the support portion 260 can be inserted into the tube 220 more smoothly. A plurality of second coupling grooves 280 are formed so as to be symmetrical to the shape.

  FIG. 4 is a perspective view showing the slip bush of the universal joint according to the first embodiment of the present invention, and FIG. 5 is a longitudinal sectional view showing the universal joint according to the first embodiment of the present invention. FIG. 6 is a cross-sectional view of a main part of the power transmission unit showing a state in which a pin is inserted in the slip bush according to the first embodiment of the present invention.

  As illustrated, the slip bush 240 according to the first embodiment of the present invention serves to mediate the shaft 210 and the tube 220, but is formed of a plastic material so that the shaft 210 is drawn into or pulled out of the tube 220. Providing a suitable frictional force between the shaft 210 and the tube 220 to transmit the rotational force generated by the steering wheel (not shown) between the shaft 210 and the tube 220; It absorbs the kick-back load that is reversely input through the wheel during traveling, and improves the steering feeling.

  The slip bush 240 is formed in a hollow cylindrical shape, and the elastic portions 250 having a C-shaped cross section that are assembled while being crimped when being attached to the tube 220 are arranged at predetermined intervals along the circumference of the slip bush 240. When the plurality of elastic parts 250 are formed so as to be separated from each other, and the rotational torque is applied to the universal joint 200 to cause twisting, the inner peripheral surface of the tube 220, that is, the second coupling groove. A support portion 260 into which a plurality of pins 270 in contact with 280 are inserted and supported is provided, and the length of the slip bush 240 is the length of the first coupling groove 230 formed in the shaft 210. Can be changed.

  On the other hand, the elastic portion 250 having a C-shaped cross section formed along the circumference of the slip bush 240 has a hollow cylindrical shape, and a constant surface of a portion formed to protrude on the outer peripheral surface side of the slip bush 240 is in the longitudinal direction. When the slip bush 240 is inserted into the tube 220 by being cut in a notched form, the slip bush 240 is inserted while being crimped, and the C-shape is crimped with noise due to an increase in the clearance generated when the universal joint 200 is twisted. The elastic part 250 of the cross section can be minimized while expanding.

  In addition, it is preferable that three elastic portions 250 having a C-shaped cross section are formed in the axial direction of the slip bush 240 along the circumference of the slip bush 240. However, the present invention is not limited to this, and play caused by twisting is not limited thereto. At least one or more may be formed as long as the increase in gap and noise can be minimized.

  And the power transmission part arrange | positioned between the elastic parts 250 of a C-shaped cross section is arranged repeatedly or sequentially along the circumference of the slip bush 240 together with the elastic parts 250 so as to fix the pins 270 and the pins 270. And a support portion 260 configured as described above. The support portion 260 is formed on both end portions of the slip bush 240, and an insertion hole 262 into which both end portions of the pin 270 are inserted is formed.

  As described above, since both end portions of the pin 270 are sandwiched between the insertion holes 262 formed in the support portion 260, the outer peripheral surface of the pin 270 becomes the inside of the tube 220 when the universal joint 200 is twisted. It serves to improve the strength and rigidity of the universal joint 200 while being in contact with the circumferential surface, that is, the second coupling groove 280 and the outer circumferential surface of the shaft 210, that is, the first coupling groove 230.

  Such a pin 270 is fixed by being inserted between insertion holes 262 formed in the support portion 260 at both end portions thereof, but the pin 270 is smoothly inserted and fixed in the support portion 260. Fixing portions 274 are formed at both side end portions of the 270, and the fixing portion 274 is formed by cutting the both side end portions of the pin 270 by a predetermined thickness and tapering them as shown in FIG. 260, and in particular, as shown in FIG. 6 (b), the cross section of the fixing portion 274 can be processed into a hemispherical shape having a semicircular shape and inserted into the support portion 260. .

  At this time, the insertion hole 262 of the support portion 260 into which the fixing portion 274 of the pin 270 is inserted is also processed into a shape corresponding to the shape of the fixing portion 274, so that the fixing portion 274 is inserted into the power transmission portion 260 more smoothly. Of course, it is preferable to maximize the fixing force between the support portion 260 and the pin 270.

  By forming tapered portions 272 that are smoothly tapered by a predetermined length at both end portions of the pin 270, when the shaft 210 is pulled into the tube 220, the end portions of the pin 270 are formed. As a result, the first coupling groove 230 formed on one side of the shaft 210 can be prevented or minimized from being worn, and therefore, the occurrence of a clearance between the tube 220 and the shaft 210 can be minimized to reduce the shaft 210. The effect of reducing the noise between the tube 220 and the tube 220 is obtained.

  Further, like the elastic part 250, the three pins 270 are preferably formed in the axial direction of the slip bush 240. However, the present invention is not limited to this, and the strength and rigidity of the universal joint 200 can be improved. If possible, at least one or more may be formed.

  The outer diameter of the pin 270 is slightly smaller than the inner diameter of the second coupling groove 280 of the tube 220 and the first coupling groove 230 of the shaft 210 with which the pin 270 contacts. The pin 270 contacts the second coupling groove 280 of the tube 220 to generate a frictional force only when the universal joint 200 is twisted, so that the strength of the universal joint 200 can be reduced. Further, it is preferable that the rigidity can be improved.

  In addition, the pins 270 attached along the circumference of the slip bush 240 provide a predetermined frictional force when the shaft 210 is pulled into the tube 220 with the rotational torque applied to the universal joint 200. However, in order to ensure strong torsional strength, it is preferable to be formed of high carbon steel or the like having excellent wear resistance. However, the pin 270 is not necessarily limited to this, and the second coupling groove 280 of the tube 220 and the shaft are not necessarily limited thereto. Of course, an appropriate frictional force can be provided while being in contact with the first coupling groove 230 of 210, and any other material can be formed as long as sufficient strength can be provided.

  As described above, the slip bush 240 according to the present invention is inserted into the tube 220 in a state where the plurality of elastic portions 250 are crimped along the circumference, so that the universal joint 200 is crimped even if the twist occurs. The elasticity of the elastic part 250 having the C-shaped cross section can minimize the increase in the clearance due to wear and pressing and the generation of noise, and of course, a fine interval so as not to contact the second coupling groove 280 of the tube 220 in normal times. However, when the tube 220 and the shaft 210 are pulled or pulled out while the universal joint 200 is twisted, the pin 270 attached to the slip bush 240 is connected to the inner peripheral surface of the tube 220. The strength and rigidity of the universal joint 200 by generating a predetermined frictional force in contact with the It can be.

  FIG. 7 is an exploded perspective view showing a universal joint according to the second embodiment of the present invention, FIG. 8 is a perspective view showing a slip bush of the universal joint according to the second embodiment of the present invention, and FIG. It is principal part sectional drawing of the power transmission part which shows the state in which the pin in the slip bush which concerns on 2nd Embodiment of the invention was inserted.

  The second embodiment of the present invention is substantially the same as the first embodiment described above except for the configuration in which the pin 270 is attached to the support portion 260. Therefore, in the following, the components of the second embodiment and these components will be described. Detailed description of the same operations as those in the first embodiment will be omitted.

  The slip bush 240 according to the second embodiment of the present invention also serves to mediate the shaft 210 and the tube 220. However, when the shaft 210 is drawn into or pulled out of the tube 220, the slip bush 240 and the tube 220 are formed. A function of providing an appropriate frictional force with the tube 220 to transmit a rotational force generated from a steering wheel (not shown) between the shaft 210 and the tube 220, and when traveling, via a wheel. It absorbs the kick-back load that is input in reverse and improves the steering feeling.

  Such a slip bush 240 is formed in a hollow cylindrical shape, and when attached to the tube 220, the elastic part 250 having a C-shaped cross section assembled while being crimped is provided at predetermined intervals along the circumference of the slip bush 240. When the plurality of elastic parts 250 are spaced apart and formed between the plurality of elastic portions 250 and a rotational torque is applied to the universal joint 200 to cause twisting, the inner peripheral surface of the tube 220, that is, the second coupling groove 280. A support portion 260 into which a plurality of pins 270 that are in contact with each other is inserted and supported is provided. The length of the slip bush 240 depends on the length of the first coupling groove 230 formed in the shaft 210. Can be changed.

  When the slip bush 240 is formed of a plastic material, the pin 270 is properly disposed in the mold of the slip bush 240 in consideration of the position of the power transmission unit and the twist in the longitudinal direction, and then integrated with the slip bush 240. By injection molding, the support portion 260 is completely fixed.

  At this time, as shown in FIG. 9, both end portions of the pin 270 are precisely processed into a gently inclined taper so that the plastic resin can flow smoothly during injection molding, and will be supported in the future. The pin 270 inserted into the portion 260 cannot be removed. The unexplained reference numeral 276 in FIG. 9 indicates the trace of the pin fixing core member that is provided in the mold at the time of injection molding and used to fix the pin 270.

  On the other hand, it is preferable that the pin 270 has a diameter slightly larger than the diameter of the support portion 260 in consideration of the tolerance, and the intermediate fixed portion of the pin 270 is located on the outer peripheral side and the inner peripheral side of the slip bush 240 between the both side support portions 260. It is preferable that the exposed portion of the pin 270 is in close contact with the first coupling groove 230 of the shaft 210 and the second coupling groove 280 of the tube 220 maintains a minimum space.

  In this manner, by forming the tapered portions 272 that are smoothly tapered by a predetermined length at both side end portions of the pin 270, when the shaft 210 is drawn into the tube 220, the end portions of the pins 270 Since the first coupling groove 230 formed on one side of the shaft 210 can be prevented or minimized, it is possible to minimize the occurrence of a clearance between the tube 220 and the shaft 210, and An effect of reducing noise between the tube 220 is obtained.

  Further, like the elastic portion 250, it is preferable that three pins 270 are formed in the axial direction of the slip bush 240. However, the present invention is not limited to this, and the universal joint 200 can be improved in strength and rigidity. At least one or more may be formed.

  The outer diameter of the pin 270 is formed to be smaller than the inner diameter of the second coupling groove 280 of the tube 220 with which the pin 270 comes into contact with the second coupling groove 280 of the tube 220 during normal operation. The pin 270 contacts the second coupling groove 280 of the tube 220 to generate a frictional force only when the universal joint 200 is twisted, and the strength and rigidity of the universal joint 200 are improved. It is good to be able to.

  In addition, the pins 270 attached along the circumference of the slip bush 240 provide a predetermined frictional force when the shaft 210 is pulled into the tube 220 with the rotational torque applied to the universal joint 200. However, in order to ensure strong torsional strength, it is preferable to be formed of high carbon steel or the like having excellent wear resistance. However, the pin 270 is not necessarily limited to this, but the second coupling groove 280 of the tube 220 and the shaft Of course, an appropriate frictional force can be provided while being in contact with the first coupling groove 230 of 210, and any other material can be formed as long as sufficient strength can be provided.

  Further, in order to increase the sliding sensibility as well as the durability, after injection molding is completed, a material such as Teflon (registered trademark) is applied to the entire outer peripheral surface or inner peripheral surface of the slip bush 240 and cured. Thus, the lubricating coating layer can be coated.

  As described above, the slip bush 240 according to the present invention is inserted into the tube 220 in a state in which the plurality of elastic portions 250 are crimped on the outer peripheral surface, so that even if the universal joint 200 is twisted, the slip bush 240 is crimped. The elasticity of the elastic part 250 having a C-shaped cross section can minimize the increase in the clearance due to wear and pressing and the generation of noise, and of course maintain a fine interval so as not to contact the second coupling groove 280 of the tube 220 in normal times. However, when the tube 220 and the shaft 210 are pulled or pulled out while the torsion is applied to the universal joint 200, the pin 270 attached to the slip bush 240 is in contact with the inner peripheral surface of the tube 220. To generate a predetermined frictional force and improve the strength and rigidity of the universal joint 200. That.

  The above description is merely illustrative of the present invention, and a person having ordinary knowledge in the technical field to which the present invention belongs does not depart from the essential characteristics of the present invention. Various modifications are possible. Therefore, the embodiments disclosed in the present specification are not intended to limit the present invention but to explain them, and the spirit and scope of the present invention are not limited by such embodiments. The scope of the present invention should be construed by the claims, and it should be understood that all technologies within the scope equivalent thereto are included in the scope of the present invention.

It is a disassembled perspective view which shows the universal joint which concerns on a prior art. It is a perspective view which shows the slip bush which concerns on a prior art. It is a disassembled perspective view which shows the universal joint which concerns on 1st Embodiment of this invention. It is a perspective view which shows the slip bush of the universal joint which concerns on 1st Embodiment of this invention. It is a longitudinal section showing a universal joint concerning a 1st embodiment of the present invention. It is principal part sectional drawing of the power transmission part which shows the state in which the pin in the slip bush which concerns on 1st Embodiment of this invention was inserted. It is a disassembled perspective view which shows the universal joint which concerns on 2nd Embodiment of this invention. It is a perspective view which shows the slip bush of the universal joint which concerns on 2nd Embodiment of this invention. It is principal part sectional drawing of the power transmission part which shows the state in which the pin in the slip bush which concerns on 2nd Embodiment of this invention was inserted.

100, 200 ... Universal joint 110, 220 ... Tube 120, 210 ... Shaft 130, 240 ... Slip bush 140, 250 ... Elastic part 150 ... Solid part 262 ... Insertion hole 270: Pin 272: Tapered portion 274: Fixed portion

Claims (6)

A universal joint including a hollow tube, a slip bush inserted into the tube, and a shaft coupled to the tube via the slip bush,
The slip bush
A power transmission unit provided with a pin disposed in the axial direction along the circumference of the slip bush, and a support unit that supports both ends of the pin;
Wherein it is arranged along the circumference of the slip bush, and is spaced apart from said power transmission unit, viewed contains one side and the elastic portion of the C-shaped cross-section which is notched in the axial direction, and
The universal joint according to claim 1, wherein tapered portions are formed at both end portions of the pin .   An insertion hole is formed in the support part located at both side ends of the slip bush, and a fixing part to be inserted into the insertion hole of the support part is formed at both side ends of the pin. Item 2. The universal joint according to item 1.   2. The universal joint according to claim 1, wherein at least one power transmission unit having the pin is provided and is spaced apart along the circumference of the slip bush. 3.   2. The universal joint according to claim 1, wherein at least one elastic portion having a C-shaped cross section is provided, and is separated along a circumference of the slip bush.   The universal joint according to claim 1, wherein the pin is injection-molded integrally with the slip bush and fixed to a support portion. The universal joint according to claim 1, wherein the slip bush is coated with a lubricating coating layer.

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